@inproceedings{akbik2018contextual,
  author = {Akbik, Alan and Blythe, Duncan and Vollgraf, Roland},
  title = {Contextual String Embeddings for Sequence Labeling},
  booktitle = {Proceedings of the 27th International Conference on Computational Linguistics},
  year = {2018},
  publisher = {Association for Computational Linguistics},
  pages = {1638--1649},
  location = {Santa Fe, New Mexico, USA},
  url = {http://aclweb.org/anthology/C18-1139}
}